html,
body,
div,
span,
applet,
object,
iframe,
h1,
h2,
h3,
h4,
h5,
h6,
p,
hr,
blockquote,
pre,
a,
abbr,
acronym,
address,
big,
cite,
code,
del,
dfn,
em,
img,
ins,
kbd,
q,
s,
samp,
small,
strike,
strong,
sub,
sup,
tt,
var,
b,
u,
i,
center,
dl,
dt,
dd,
ol,
ul,
li,
fieldset,
form,
label,
legend,
input,
button,
select,
textarea,
table,
caption,
tbody,
tfoot,
thead,
tr,
th,
td,
article,
aside,
canvas,
details,
embed,
figure,
figcaption,
footer,
header,
hgroup,
menu,
nav,
output,
ruby,
section,
summary,
time,
mark,
audio,
video {
    box-sizing: border-box;
    padding: 0;
    margin: 0;
    font: inherit;
    font-size: 100%;
    vertical-align: baseline;
    border: none;
    outline: none;
    -webkit-tap-highlight-color: transparent; // 去掉点击对象时默认的灰色半透明覆盖层(iOS)或者虚框(Android)
    -webkit-user-select: none; // 禁止选择文字
}

html {
    -ms-text-size-adjust: 100%;
    -webkit-text-size-adjust: 100%; // 禁止文字自动调整大小(默认情况下旋转设备的时候文字大小会发生变化)
    //-webkit-overflow-scrolling: touch;
    -webkit-font-smoothing: antialiased; // 字体抗锯齿
    -moz-osx-font-smoothing: grayscale;
}

input,
select,
textarea {
    border: none;
    -webkit-appearance: none; // 清除内阴影
    -webkit-user-select: auto !important; // 否则ios下输入框无法输入
}

textarea {
    overflow: auto;
    resize: none;
}

h1,
h2,
h3,
h4,
h5,
h6 {
    font-size: 100%;
    font-weight: normal;
}

address,
caption,
cite,
code,
dfn,
th,
var,
i,
em {
    font-style: normal;
}

abbr,
acronym {
    // 去掉firefox下此元素的边框
    border: none;
    font-variant: normal;
}

ul,
ol {
    list-style: none;
}

del {
    text-decoration: line-through;
}

ins,
a {
    text-decoration: none;
}

a,
img {
    -webkit-touch-callout: none; // 禁用长按页面时的弹出菜单(iOS下有效)
}

img {
    border: none;
    /*display: block;*/
    vertical-align: top;
}

table {
    // 去掉各table cell的边距并让其边重合
    border-spacing: 0;
    border-collapse: collapse;
}

blockquote,
q {
    quotes: none;
}

blockquote:before,
blockquote:after,
q:before,
q:after {
    content: '';
}

//统一上标和下标
sub,
sup {
    position: relative;
    font-size: 75%;
    line-height: 0;
    vertical-align: baseline;
}

sup {
    top: -0.5em;
}

sub {
    bottom: -0.25em;
}